Remotely Hosted HTA File Executed Via Mshta.EXE — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-08-08 / 2023-02-06.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d5af7276f3248ae81e0521b1cd97c9f363a05482744b1b3a223dd459ed9b7921

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Remotely Hosted HTA File Executed Via Mshta.EXE
id: b98d0db6-511d-45de-ad02-e82a98729620
status: test
description: Detects execution of the "mshta" utility with an argument containing the "http" keyword, which could indicate that an attacker is executing a remotely hosted malicious hta file
references:
    - https://www.trendmicro.com/en_us/research/22/e/avoslocker-ransomware-variant-abuses-driver-file-to-disable-anti-Virus-scans-log4shell.html
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-08-08
modified: 2023-02-06
tags:
    - attack.execution
    - attack.stealth
    - attack.t1218.005
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\mshta.exe'
        - OriginalFileName: 'MSHTA.EXE'
    selection_cli:
        CommandLine|contains:
            - 'http://'
            - 'https://'
            - 'ftp://'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.trendmicro.com/en_us/research/22/e/avoslocker-ransomware-variant-abuses-driver-file-to-disable-anti-Virus-scans-log4shell.html